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Flashcards in The Menstrual Cycle Deck (22)
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1
Q

What is the term given to describe the inception of menstruation around puberty?

A

Menarche

2
Q

What triggers the menarche?

A

Increasing GnRH levels

3
Q

What comprises an ovarian follicle?

A

An oocyte surrounded by granulosa and theca cells

4
Q

What is the function of theca cells?

A

Produce androgens

5
Q

What is the function of granulosa cells?

A

Conversion of androgens (using aromatase) to oestrogens

6
Q

What are the two key phases of the menstrual cycle?

A
  1. Follicular phase
  2. Luteal phase
7
Q

Which days does the follicular phase typically occupy within the menstrual cycle?

A

Days 1 - 12

8
Q

The follicular phase begins with __________

A

The follicular phase begins with menstruation

9
Q

Which hormone begins to rise first in the follicular phase and what is its impact?

A

Gonadotrophin releasing hormone (GnRH)

Increases secretion of FSH and LH from the anterior pituitary

10
Q

Which hormone acts on theca cells and what is the outcome?

A

LH

Androgen production

11
Q

Which hormone cats on granulosa cells and what is the outcome?

A

FSH

Oestrogen production

12
Q

___________ levels rise throughout the follicular phase

A

Oestrogen levels rise throughout the follicular phase

13
Q

____ causes maturation of follicles until a _________ (dominant) follicle emerges

A

FSH causes maturation of follicles until a Graafian (dominant) follicle emerges

14
Q

Between which days does a surge in LH occur and what does it cause?

A

12-14

Ovulation

15
Q

High levels of oestrogen have what impact on which hormone?

A

Inhibition of FSH

16
Q

What happens to the remaining follicle after ovulation?

A

It becomes the corpus luteum and secretes progesterone (and some oestrogens)

17
Q

What effect does progesterone have?

A
  1. Increases thickness and secretory activity of endometrium
  2. Increases basal body temperature
  3. Increases cervical mucus thickness
  4. Aids glandular development in the breasts
18
Q

What effect do high progesterone levels have on which two other hormones?

A

Inhibition of FSH and LH

19
Q

What happens when there is failure of fertilisation?

A
  1. Degeneration of the corpus luteum
  2. Fall in progesterone levels
  3. Fall in oestrogen levels
  4. Vasospasm of of arterioles supplying endometrium
  5. Necrosis of endometrium and menstruation
20
Q

A fall in progesterone levels has which effect on which two other hormones?

A

Rise in FSH and LH

(inhibitory effect removed)

21
Q

What is the most potent oestrogen produced and what does it cause?

A

Oestradiol

  1. Secondary sexual charcateristics
  2. Contributes to bone and CV health
22
Q

Which hormone stimulates the transformation of the empty follicle to the corpus luteum?

A

LH